Hydrothermal and soft-templating synthesis of mesoporous NiCo2O4 nanomaterials for high-performance electrochemical capacitors

Mesoporous nickel cobaltite (NiCo2O4) nanoparticles were synthesized via a hydrothermal and soft-templating method through quasi-reverse-micelle mechanism. The physicochemical properties of the NiCo2O4 materials were characterized via X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectra, and nitrogen sorption isotherms measurements. The electrochemical performances of the NiCo2O4 electrode were investigated by cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy tests. The obtained NiCo2O4 materials exhibit typical mesoporous structures, with an average particle size of about 200 nm, a specific surface area of 88.63 m(2) g(-1), and a total pore volume of 0.337 cm(3) g(-1). The facile electrolytes penetration for the mesoporous structures favors high-performance of the NiCo2O4 electrode. The NiCo2O4 electrode shows a high specific capacitance (591 F g(-1) at 1 A g(-1)), high-rate capability (248 F g(-1) at 20 A g(-1)), and a good cycling behavior for tested 3,000 cycles, indicating a promising application for electrochemical capacitors.